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We investigated the amplitude of medium scale traveling ionospheric disturbances (MSTIDs, with periods 25–100 min) and their dependence on the solar activity using 16 years data of the rapid run‐ionosonde operating at high latitudes (67° $67{}^{\circ}$N, Sodankylä, Finland). A deep learning neural network was applied to ionograms to extract critical frequency of the F2 region (foF2) with a 1 min time resolution. Then, we analyzed the relative amplitude of MSTIDs (i.e., 2δ $2\delta $foF2/foF2), which corresponds to the amplitude of atmospheric gravity waves (AGWs) causing MSTIDs. The amplitude of AGWs propagating upward increases with height due to the decreasing density of the air, and hmF2 varies depending on local time, seasonal and solar activity conditions. To account for this effect, we calculated a corrected MSTID amplitude by normalizing the relative amplitude for the air density at the hmF2. The corrected amplitudes show no clear dependence on F10.7 during winter (0–12 UT), equinox (20‐01 UT) and summer (19‐01 UT), while a positive dependence of corrected amplitudes on F10.7 was observed during winter and equinox, in 14–22 UT and 15–19 UT, respectively. Corresponding to the dependence behaviors of corrected and relative amplitudes, two likely mechanisms of MSTIDs, AGWs from the lower atmosphere and auroral sources, are inferred. Their subsequent roles in the solar activity dependence of MSTID amplitudes were separately discussed, although in reality, the observed dependence is complex and often involves several mechanisms together. Plain Language Summary: HF radio frequencies used for ground and/or space‐ground communications and navigation systems often face challenges due to traveling ionospheric disturbances (TIDs), which can degrade the propagation of radio signals. Employing deep learning for rapid‐run ionosonde data enabled us to monitor TIDs at Sodankylä Geophysical Observatory (SGO) effectively. Daytime TID occurrences are often associated with disturbances triggered from the lower atmosphere (AGWs). However, the increase in hmF2, which reduces the likelihood of AGWs initiated from the lower atmosphere reaching the region of peak ionization, and the expansion of the auroral oval due to frequent substorms, shift the nighttime triggers to auroral electrodynamics in high latitude regions. In this paper, we examine the dependence of MSTID amplitudes on solar activity after applying a new correction approach. Key Points: foF2 obtained from 1 min ionograms through deep learning enabled us to conduct long‐term MSTID investigations in high latitudesCorrection of MSTID amplitudes to the neutral density level at different hmF2 altitudes properly describes the solar activity dependenceCorresponding to the causing mechanisms, the high‐latitude corrected MSTID amplitudes infer different types of dependence on solar activity [ABSTRACT FROM AUTHOR]

The potential of deep learning for the investigation of medium scale traveling ionospheric disturbances (MSTIDs) has been exploited through the Sodankyla rapid-run ionosonde in this statistical study. The complementing observations of the Sodankyla ionosonde with those of the Sodankyla meteor radar reveals the diurnal and seasonal occurrence rate of high-latitude MSTIDs in the recent low solar activity period, 2018-2020. In our results, the daytime, nighttime and dusk MSTIDs are predominantly identified during winter, summer, and equinoctial months, respectively. The winter daytime higher (lower) occurrence rate is well correlated with the lower (higher) altitude of the height of the F2-layer peak (hmF2), and the low occurrence rate of the summer daytime is well correlated with the mesosphere-lower-thermosphere wind shear and higher gradient of temperature. Relatively high occurrence rate (>0.4) of summer nighttime MSTIDs has a general--but not one-to-one agreement--with post-noon to evening IU (eastward auroral current index) inferred ionospheric conductivity. Rather, we see a one-to-one relationship between the summer nighttime MSTIDs and zonal wind shear suggesting that the wind shear-induced electrodynamic processes could play significant roles for higher occurrence rate of MSTIDs. Furthermore, significant MSTIDs with ~0.4 occurrence rate are so far revealed during spring and autumn transition periods. The enhanced nighttime MSTID amplitudes during the equinox are observed to be well correlated with IL index (westward auroral current indicator) suggesting that the particle precipitation during substorms could be the primary cause. [ABSTRACT FROM AUTHOR]

In this paper equatorward propagating large scale traveling ionospheric disturbance (LSTID) on 17 March 2015 were investigated using the Statistical Angle‐of‐Arrival and Doppler Method for GPS (SADM‐GPS) radio interferometry technique in data‐scarce East Africa. To apply the SADM‐GPS method, 5 GPS arrays each with 3 GPS receivers arranged in a triangular geometry were used. Our results show that during 15:00–18:00 UT on 17 March, TIDs with mean horizontal velocities between 161.9 and 464.4 m/s were observed. Using the wavelet analysis, the periods of TIDs in a range of 51–69 min that qualify to LSTIDs were revealed. The peak‐to‐peak phase shift of detrended total electron content (TEC) over latitudes in this study confirms the equatorward TID propagation, which was obtained by the SADM‐GPS technique. A pair of magnetometers were used to infer E × B drift and an adequate agreement was found with Swarm satellites derived plasma density that enabled us to explain the behaviour of ionospheric irregularity during the main phase of the geomagnetic storm. Moreover, significant TEC enhancement (reaching ∼20%–105%) were captured by GPS arrays during the period of TID propagation. Nevertheless, the rate of change of TEC (ROT) and ROT index (ROTI) show wavy structures that reflect TID effects over ionospheric modulations during the post noon to evening hours of 17 March 2015. Key Points: Multiple GPS arrays having a triangular orientation are potential mechanisms to observe traveling ionospheric disturbances (TID) propagation using Statistical Angle‐of‐Arrival and Doppler Method for GPSTIDs can be identified as a wavy quenches embedded in ionospheric irregularitiesThe geomagnetic storm event of 17 March 2015 have a damping effect on ionospheric irregularities in East African longitude [ABSTRACT FROM AUTHOR]

Objectives: To analyse the outcomes of COVID‐19 vaccination by vaccine type, age group eligibility, vaccination strategy, and population coverage. Design: Epidemiologic modelling to assess the final size of a COVID‐19 epidemic in Australia, with vaccination program (Pfizer, AstraZeneca, mixed), vaccination strategy (vulnerable first, transmitters first, untargeted), age group eligibility threshold (5 or 15 years), population coverage, and pre‐vaccination effective reproduction number (Reffv¯) for the SARS‐CoV‐2 Delta variant as factors. Main outcome measures: Numbers of SARS‐CoV‐2 infections; cumulative hospitalisations, deaths, and years of life lost. Results: Assuming Reffv¯ = 5, the current mixed vaccination program (vaccinating people aged 60 or more with the AstraZeneca vaccine and people under 60 with the Pfizer vaccine) will not achieve herd protection unless population vaccination coverage reaches 85% by lowering the vaccination eligibility age to 5 years. At Reffv¯ = 3, the mixed program could achieve herd protection at 60‒70% population coverage and without vaccinating 5‒15‐year‐old children. At Reffv¯ = 7, herd protection is unlikely to be achieved with currently available vaccines, but they would still reduce the number of COVID‐19‐related deaths by 85%. Conclusion: Vaccinating vulnerable people first is the optimal policy when population vaccination coverage is low, but vaccinating more socially active people becomes more important as the Reffv¯ declines and vaccination coverage increases. Assuming the most plausible Reffv¯ of 5, vaccinating more than 85% of the population, including children, would be needed to achieve herd protection. Even without herd protection, vaccines are highly effective in reducing the number of deaths. [ABSTRACT FROM AUTHOR]

Protein arginine methyltransferase PRMT5 interacts with human SWI/SNF complexes and methylates histones H3R8 and H4R3. To elucidate the role of PRMT5 in human cancer, we analyzed PRMT5 expression in normal human B lymphocytes and a panel of lymphoid cancer cell lines as well as mantle cell lymphoma (MCL) clinical samples. We show that PRMT5 protein levels are elevated in all cancer cells, including clinical samples examined despite its low rate of transcription and messenger RNA stability. Remarkably, polysome profiling revealed that PRMT5 mRNA is translated more efficiently in Mino and JeKo MCL cells than in normal B cells, and that decreased miR-92b and miR-96 expression augments PRMT5 translation. Consequently, global methylation of H3R8 and H4R3 is increased and is accompanied by repression of suppressor of tumorigenecity 7 (ST7) in lymphoid cancer cells. Furthermore, knockdown of PRMT5 expression reduces proliferation of transformed JeKo and Raji cells. Thus, our studies indicate that aberrant expression of PRMT5 leads to altered epigenetic modification of chromatin, which in turn impacts transcriptional performance of anti-cancer genes and growth of transformed lymphoid cells. [ABSTRACT FROM AUTHOR]

Poly(A) polymerase was extracted from isolated nuclei of rat liver and a rapidly growing solid tumor (Morris hepatoma 3924A). The enzyme from each tissue was purified by successive chromatography on DEAE-Sephadex, phosphocellulose. hydroxyapatite and QAE-Sephadex. Purified enzyme from both liver and tumor was essentially homogeneous as judged by polyacrylamide gel electrophoresis. Under nondenaturing conditions, enzyme activity corresponded to visible protein and, upon denaturation, a single polypeptide was detected The enzymes had absolute requirements for Mn2+ as the divalent ion, ATP as the substrate and an oligonucleotide or polynucleotide as the primer. Both enzymes were inhibited by sodium pyrophosphate, N-ethylmaleimide, Rose Bengal, cordycepin 5'-triphosphate and several rifamycin derivatives. The reactions were unaffected by potassium phosphate, α-amanitin and pancreatic ribonuclease However, the liver and hepatoma enzymes differed from each other with respect to apparent Km, primer saturation levels and sensitivity to pH changes. The most striking differences between the enzymes were in their calculated molecular weights (liver, 48000, hepatoma, 60000) and amino acid compositions Finally, the level of the hepatoma enzyme relative to that of the liver enzyme was at least 1.5-fold higher when expressed per mg DNA. [ABSTRACT FROM AUTHOR]

The synthesis and degradation of poly(A) were examined in wheat germ lysates under conditions used for protein synthesis. The lysate contained both poly(A)-polymerizing and poly(A)-hydrolytic activities. The synthetic activity was dependent on the presence of either poly(A) or polyadenylated mRNA as primer. Concurrent with the synthesis of poly(A), radioactivity was released from labeled poly(A) and from the poly(A) region of mRNA. Both poly(A) synthesis and hydrolysis were independent of Mn2+ and could proceed in the presence of Mg2+, the major divalent metal ion required for protein synthesis. The synthetic activity was favoured at high (1 mM) ATP concentration, whereas the hydrolytic activity was maximal in the absence of ATP or at low (0.1 mM) ATP concentration. These data indicate that the steady-state length of the poly(A) moiety of mRNAs in the cytoplasm may be regulated by the levels of ATP. Translation products of polyadenylated mRNAs isolated from myeloma cells before and after partial deadenylation were separated by dodecylsulfate/polyacrylamide gel electrophoresis. Shortening of the poly(A) moiety did not alter the relative amounts of the peptides synthesized, indicating that this process does not involve a preferential breakdown of certain species of mRNA. [ABSTRACT FROM AUTHOR]

The functional role of transition metals in poly(A) synthesis was elucidated by investigating the effect of the metal chelator o-phenanthroline on purified nuclear poly(A) polymerase. This chelator inhibited the enzyme activity in a manner competitive with respect to the polynucleotide primer concentration, o-Phenanthroline was a non-competitive inhibitor with regard to ATP concentration and an 'uncompetitive' inhibitor with regard to dithiothreitol levels. The metal content of the purified enzyme preparations from rat liver and Morris hepatoma 3924A was determined using atomic absorption spectrometry. Of the transition metals measured, only zinc was present in detectable quantities, at levels less than 1 mol:mol of enzyme. Hepatoma enzyme contained 2-3 times as much zinc as the corresponding liver enzyme. Hepatoma poly(A) polymerase was also radioactively labelled in vivo by injection of tumor-bearing animals with 65Zn. Dialysis experiments with highly purified radiolabelled poly(A) polymerase showed that the enzyme zinc complex was labile and that a reduction in 65Zn content correlated with a loss in enzyme activity. These data indicate that (a) poly(A) polymerase is a zinc-containing protein, (b) this metal plays a role in the interaction between enzyme and its polynucleotide primer, (c) relative to hepatoma poly(A) polymerase, the liver enzyme forms a less stable complex with zinc, and (d) the loss of zinc from poly(A) polymerase upon extensive purification may explain its low zinc content relative to that reported for other proteins. [ABSTRACT FROM AUTHOR]